Starter for induction-motors.



P. R. ELLGUTH.

STARTER FOR INDUCTION MOTORS.

APPLICATION FILED JUNE 18, 1914.

I 0 m l w 7 L M .S W H MW MZ Du m D1 Qd a'ifiessesx P. R. ELLGUTH.

sumsn FOR mnucnou morons.

APPLICATION FlLED JUNE 13, 1914. 1,167,486, Patented Jan. 11, 1916.

2 SHEETS-SHEET 2.

mm Nh RN PAUL R. ELLGUTH, OF CHICAGO, ILLINOIS.

STARTER FGR INDUCTION-MOTORS.

. Specification of Letters Patent.

Patented Jan. 11, 1916.

Application filed June 13, 1914. Serial No. 844,918.

T 0 all whom it may concern Be it known that I, PAUL R. ELLGUTH,

citizen of the United States, residing at Chicago, in the county of Cookand State of Illinois, have invented certain new and useful Improvementsin Starters for Induction-Motors; and I do hereby declare the followingto be a full, clear, and exact description of the invention, such aswill enable others skilled in the art to which it appertains to make anduse the same.

My invention relates to magnetically actuated starters for electricmotors and more particularly to the class of starters used withinduction motors requiring a change in the connections for some of theirwind ings during their starting period.

One object of my invention is to provide a. magnetically actuatedstarter adapted to change certain circuit connections when the currentflowing through a portion of the motor: windings reaches a predeterminedvolume.

Another object is to provide a simple and positive means for changingthe initial slow movement of a magnetically actuated mechanism to afinal rapid movement, whereby the switching of the circuit connectionsis effected with a minimum of arcing at the contacts. I

Still another object is to provide a simple gravity actuated meanswhereby a similarly rapid operation of the switching means in theopposite direction is effected upon a re duction of the current throughthe starter.

Other objects will appear from the following specification and from thedrawings accompanying the same.

The starter of. my invention is particularly applicable for use inconnection with a single phase induction motor having a porticn of itsstator windings so arranged that the same may produce a phase-splittingeffect for the purpose of creating a rotating field of high torqueduring the starting of the motor, as more fully disclosed in my co-pending application for a patent on an induction motor and startertherefor, filed May28th, 1914, Serial No. 841415, and is shown in thisapplication in the accompanying drawings, in. which Figure 1 is a sideelevation of the starter of my invention. Fig. 2 is a front elevation ofthe same. Fig. 3 is a horizontal section through the starter along theline 33 of Fig. 1. Fig. 4 is an enlarged detail iew of the auxiliarycontact mechanism for temporarily connecting one of the magnet windingsof the starter to the circuit. Fig. 5 is a fragmentary side elevation ofthe starter after the motor has been brought up to speed. Fig. 6 is adiagrammatic view of the starter of my invention as connected to thecircuits of an induction motor of the type shown in the co-pendingpatent appli cation heretofore mentioned.

In the embodiment of the drawings, the

starter of my invention consists of an electromagnet having twowindings, the said magnet being mounted u on a base 1 of slate or otherinsulating material, which base is preferably the front of a rheostatcontaining the resistance 33. The magnet preferably consists of an ironframe 3 supporting an insulating tube 4 having a square bore. Slidablypositioned in this tube is a laminated core 5 composed of strips of softiron riveted together, this core having an elongated slot 6 near itslower end. Mounted upon the forward portion 7 of the magnet frame aretrunnions 8 for an axis 9. which axis serves as a pivot for a rockingbar 10. The said rocking bar has at its opposite ends contact members 11and 12, each composed of thin strips of copper or bronze, and eachsuitably insulated from the rocking bar 10, each of which contactmembers is adapted to bridge across a pair of metal contacts disposed inproximity to the said bridging contact. Thus the upper bridging contact11 is adapted when the rocking bar is in one extreme of its normalposition (as in Fig. 5) to contact with and bridge across terminals 13and 14, the said terminals be ing mounted, respectively, upon slatepillars 15 and 16 carried by the base 1. Likewise, the lower bridgingcontact 12 is adapted, when the starter is in its idle position, asshown in Fig. 1) to bridge across a pair of terminals 17 and 1.8supported, respectively, by slate posts 19, the said posts also beingmounted upon the base 1.

Extending transversely through the perforation 6 in the lowe end of thelaminated core 5 is a pin 20 whichserves as a pivotal connection for apair of links 21 and 22, the former of which is pivotally connected toan extension 23 at the lower end of the rocking arm 10. The companionlink 22 is similarly pivotally connected to an extension 2% of themagnet frame 7, which extension also has a stop 25 adapted to limit theup-.

ward movement of the link 22. The pin 20 is preferably considerablysmaller in diameter than the width of the perforation 3, therebypermitting the pin 20 to move laterally with respect to the axis of themagnet without interfering with the free vertical motion of thelaminated core Secured to the upper end of the said core 3 is a rod 26carrying a transverse member 27 having a tongue 28 pivoted at one edgeof the latter, this tongue being normall held in a positionsubstantially at right angles to the axis of the magnet by a spring 29also carried by the rod The transverse member 27, the spring :29 and aspring stop 30 disposed at the other side of the tongue 28 are allsuitably insulated from the rod 26, the member :27 being connected by afexible wire 31 to the terminal. 13, which is one of the terminals of asource of single phase current when the starter is in use.

The companion terminal 1 1 is connected to the said terminal 13 througha wire 32 and a res stance 3-3, which resistance is short-circuited whenthe upper bridging contact 11 bridges across the said terminals 13 and1%. The terminal 14: is also connected by a wire 34. to themultiple-grouped windings 35 and 36, which groups of windings are inseries with each other, as shown in Fiat *3. Connected to the junctureof the said groups of windings 35 and 3G to form a star connectiontherewith are the seriesconnected windings 37 (the said windings 35, 36and 37 being suitably disposed upon the stator of the motor), the otherend ct which series oi windings 3? is connected by a wire 38 to theterminal 18 mounted upon one of the lower posts 19. The companionterminal 17 is permanently connected by a wire 39 to the upper term nal13, thereby connecting the said terminal 1 continuously to one terminal40 of tie source of single phase current. The other terminal of thiscircuit 41-1 is connected by a wire 42 to the free end of themultiple-grouped windings 36 and through a wire 13 to one end of each ofthe magnet or solenoid windings 414i and 15, which wind ngs are upon thesquare insulating tube 4. The other end the magnet winding 44- isconnected by wires 16 and 34 to the other terminal of themultiple-grouped windings 35 of the stator and to the contact terminal14 carried by one of the rumor posts of the starter. The upper terminalof the magnet winding 45 is connected by a winding 47 to a rigid contact4.8 positioned upon the base 1 in the path of the pivoted tongue 28.

1V hen the motor is idle, the parts will be in the relative positionsshown in Fig. 6, with the lower bridging contact 12 connecting thecontacts 17 and 18, thereby connecting the line terminal 10 to theseries-joined 'indings 37 of the stator and through the resistance 33 tothe multiple-joined windings 35, while the other line terminal ll isconnected directly to the multiple-grouped windings 36. T he result willbe the production of a split-phase current in the respective starterwindings when the current is turned on, thereby producing substantiallythe effect of a three-phase current for starting the motor. The magnetwinding 1% being in shunt with the free ends of the two groups ofmultiple-connected stator windings 35 and 36, and the resistance of thestator windings being quite low, the said magnet winding will at firstreceive only a very small amount of current. *lowe er, as the motorincreases in speed, the inductive effect of the rotor windings upon thestator windings will decrease the flow of current through the saidstator windings 35 and 36, thereby causing a larger proportion of theline current to flow through the magnet winding 44. Consequently, theeffective strength of this magnet winding and its re sulting pull uponthe core 5 will gradually increase as the motor approximates its normalspeed, hence the said magnet will raise its core more and more until thetongue 29 contacts with the fixed terminal 48, thereby also connectingthe auxiliary magnet winding 4-5 to the circuit in multiple with thewinding 44. .Vhen this occurs, the effective pull of the magnet will besuddenly and greatly increased, thereby giving an additional and rapidupward motion to the core 5 and causing the tongue 28 to be drawn upwardbeyond and out of contact with the terminal 48 co-acting therewith.Owing to the pivotal mounting of the tongue 28, this will be free toswing out of alinement with the member 27 supporting the same (as shownin Fig. 1) and as soon as the tip of the tongue has passed the tip ofthe terminal 18, the spring 99 will again force the said tongue intoalinement with the supporting member 27, thereby causing a rapidbreaking of the contact at the tip of the tongue so as to avoid anyserious arcing at this point.

Vhen the magnet core is being gradually drawn up into the magnet whilethe motor is gaining in speed, this will have no effect upon the rockingbar 10 and the contacts carried thereby until the lower end of the slot6 is raised sufliciently to engage the pin 20, whereupon a furtherraising of the core 5 will raise the juncture of the links 21 and 22 soas to carry them toward the position shown in Fig. 5. By suitablyproportioning ,the length of the slot 6 and the distances between thetongue 28 and the con tact terminal 48, I cause the auxiliary magnetwinding closed through the said tongue and contact to effect the suddenfinal movement of the core after the pin 20 has already been engaged by,or at about the moment from the source of current and the resistance 33will be short-circuited by the bridging contact 11, thereby connectingthe two groups of multiple-joined stator windings 35 and 36 in serieswith each other across the line terminals 40 and 41 so that the motorwill operate after the usual fashion of single-phase induction motors.Vhen the motor is thus running, the magnet winding 44 will remaincontinuously in shunt with the active stator windings, therebymaintaining the normal connections to the circuit. When the line currentis disconnected from the motor, as by opening a switch 49, the flow ofcurrent through the double wound solenoid will cease, thereby permittinggravity to retract the core 5. In doing so, the core will be free tomove for a considerable distance before the upper end of the slot 6engages the pin 20; consequently this core will have attained aconsiderable momentum, thereby enabling the core to overcome anytendency of the links 21 and 22 to bind or remain in the position ofFig. 5. To further overcome any such tendency of the moving parts tostick or bind, I preferably interpose a compression spring 50 betweenthe upper end of the rocker arm 10 and the magnet frame 8.

While I preferably use a rocking arm for carrying the two bridgingcontacts (which coact with the terminals supported by the posts to formswitches) and preferably in-- terpose a pair of jointed links betweenthis rocker arm and the actuating core of the magnet, I do not wish tobe limited to this construction, as other transmission means might beused for imparting a relative motion to the said bridging contacts. Thusthe diagrammatic view of Fig. 6 shows that the two bridging contactsmight be moved vertically by mounting both of them slidingly upon thecore 5 and providing the latter with a pair of pins 51 adapted to engagethe said contacts when the core has been raised to a predeterminedextent, due provision being made for insulation which is not shown inthe diagram of Fig. 6. So, also, I do not wish to be limited to theparticular arrangement of pivoted tongue and spring construction as usedfor making the auxiliary and temporary contact during a por tion of thestroke of the armature core, it being obvious that these and otherdetails of construction herein disclosed might be varied considerablywithout departing from the spirit of the appended claims.

I claim as new and desire to secure by Letters Patent:

1. A motor and starter combination, including an electric motor havingan auxiliary starting winding, a movable member interposed in andforming part of the current supply circuit for the said auxiliarywinding; a pivoted lever carrying the said movable member, a solenoid incircuit with the main windings of the motor; a support and a slidingcore for the said solenoid, and apair of jointed links connected attheir free ends respectively to the said pivoted lever and the saidsupport, the common. pivot of the said jointed links being interposed inthe path of a portion of the said core. whereby the movement of the saidcore is adapted to move the said links with respect to each other.

2. A motor and starter combination, including an electric motor havingmain and auxiliary wingings, a resistance adapted to be inserted inseries with the said main windings, a solenoid having a windingcontinuously in shunt with the said main windings, a switch adapted toconnect the auxiliary winding to one terminal of the operating circuit,a second switch adapted to shortcircuit the said resistance, a movablecore for the solenoid, and transmission mechanism connecting the saidcore with both of the said switches for simultaneously operating thesaid switches by the movement of the said core.

3. A motor and starter combination, including an electric motor havingmain and auxiliary windings, a pivoted switch controlling the saidauxiliary windings, and magnetically actuated apparatus for actuatingthe said switch; the said mechanism comprising a solenoid winding cntinuously connected to the circuit, a movable core for the saidsolenoid. and connections between the said core and the saidlever-actuated switch for causing the movement of the core to actuatethe said switch.

4. A motor and starter combination, in cluding an electric motor havingmain windin s and auxiliary windings, a movable switching membercontrolling the said auxiliary windings, a solenoid subicct to the flowof current in the main windings 01' the motor, a core for the solenoid,the said core having a slotted end: 1nd a link connecting the saidmovable switching member with the slotted end of the said core, the slotin the latter affording an engagement between the core and the said linkafter the core has been moved a predetermined distance.

5. A motor and starter combination, including an electric motor havingmain and auxiliary windings, a resistance adapted to be inserted inseries with the former of the said windings, a switch member adapted toshort circuit the said resistance, another having a winding in shuntwith the former of the said motor windings; a core for the saidsolenoid, and connections between the said core and tie said rockinglever for transmitting the motion of the core to the lever to actuatethe said switching members.

6. A motor and starter combination, including an electric motor having aplurality of windings, a movable switchingmember controlling one of thesaid windings, a solenoid having a pair of windings thereon, one thereofcontinuously connected to the motor circuit; a movable core for thesolenoid, connections between the core and the switching member fortransmitting the motion of the core to the said switching member; and apair of contacts controlling the circuit connections to the other of thesaid solenoid windings. one of said contacts being carried by the saidcore.

7. A motor and starter combination, including an electric motor having aplurality of windings, a movable switching member controlling one of thesaid windings; a solenoid having a pair of windings thereon, one thereofcontinuously connected to the motor circuit; a movable core for thesolenoid; connections between the core and the switching member fortransmitting the motion of the core to tne said switching member; and apair of contacts controlling the circuit connections to the other of thesaid solenoid windings, the said contacts being adapted to contact witheach o her during a portion 01" the travel of the said core, the contactportion of one of the said contacts being pivotally mounted.

S. A motor and starter combination including an electric motor havingmain and auxiliary windings, a movable switching member controlling thesaid auxiliary windings, a solenoid subject to the flow of current inthe main windings of the motor, a core for the solenoid. connectionsbetween the core and the switching member whereby the movement of thecore will actuate the switching member, and means associated with saidconnections for preventing the core from actuating the switching memberbefore the core has been moved a predetermined distance.

9. A motor and starter combination inch in g an electric motor having aplurality of windings, a movable svitching member controlling one of sad windings: a solenoid having a pair of windings thereon, one thereofcontinuously connected to the motor circuit: and. means actuated by theflow of current through the said continuously connected solenoid windingfor momentarily moves the switching member.

11. A motor and starter combination, including an electric motor havinga plurality of windings, a movable switching member controlling one ofsaid windings. a solenoid sub ee to the flow of current in one of thewindings of the motor: a core for the solenoid connected to saidswitching member and actuated by the flow of current through saidsolenoid winding to operate the switching member. said core beinggravity-retracted: and means associated with said core and theconnections of the latter to the switchmember for ,)re cnting said coretrom actuating said connect ons until the core has dropped for apredeterm ned distance, wherebv the momentum acquired by the core whilefalling through the said d stance will cause the same to mo e the saidswitching member with considerable speed.

A motor and starter comb nation, includii an electric motor. a rtingresistance therefor, a movable switching member adapted to shortcircuitsaid resistance: a solenoid hav' a pair of windings, one thereot continously subject to the flow of current through the motor. the otherthereof adapted to be connected in shunt with the former of said solcnoid windings: a core for said solenoid: connections between said core andthe switching member for causing the movement of the core to actuatesaid member to short-circuit the said stance: and means associated withsaid core and momentarily operated during the movement of the core underthe influence of the first named solenoid winding. for connecting theother of the solenoid windings in shunt with the former. thereby causingthe joint action of said windings on the core to accelerate the movementof the core and the speed at which the latter actuates the switchingmember.

13. A. motor and starter combination includ ng an electric motor havingmain and auxiliary windings, a resistance adapted to be inserted inseries with the sa d main wind ings, a solenoid having a windingcontinuously in shunt with the said main wind ngs, a switch adapted toconnect the auxiliary winding to one terminal of the operating; circuit,a second switch adapted to shortcircuit the said resistance, a movablecore for the solenoid, transmission mechanism connecting the said corewith both of the said switches for simultaneously operating the saidswitches by the movement of the said core: and means associated withsaid core and operated at a predetermined point in the movement thereoffor accelerating the movement of said core, thereby increasing the speedat which the core operates both of said switches.

14. A motor and starter combination, including an electric motor, astarting resistance therefor, a solenoid subject to the flow of currentthrough the motor, mechanism operated by the solenoid forshort-circuiting the starting resistance, and means associated with saidmechanism and said solenoid for momentarily accelerating the speed atwhich the solenoid operates the said mechanism.

In testimony whereof I have signed my name in presence of twosubscribing witnesses.

PAUL R. ELLGUTH. Witnesses:

ALBERT SCI-IEIBLE, G. M. NEVILLE.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

